I understand and agree about the possibility of not beeing a hardware problem. I just thought hardware was a possibility...

And reading your last message, I think you must try to bootload with board type "NG or older with Atmega168" instead of "Diecimila". I think there are differences on how they handle TX and RX Atmega pins (I think Diecimila bootloader turns on pull up resistors), and other differences too. Can you try to bootload it with "NG or older w/Atmega168" and test it again?

Update: I discovered that I can upload even the problem sketches if I do a manual reset. Most sketches will upload without the reset but the ones that were having errors seem to upload ok if I reset a few seconds after starting the upload.

The board does have the 0.1uf capacitor connecting the DTR (RS232 pin 4) to ICSP reset (pin 5) and seems to work intermittently when relying on the auto reset.

I am still looking at why the auto-reset is intermittent and why one of my boards seems much more reliable than the other

I've been having problems with a serial kit I bought from the same place as you. It starts up fine, blinks fine. but I get errors when trying to upload a program. Same computer runs a real Arduino USB board perfectly. I'll try some tests on OSX, which is what I mainly use. My macbook works perfectly with the usb version, but I'll report back after some tests on that machine. I'm starting to think the extra 16 bucks is worth no struggles + USB.

I think I'll just use the USB one that works and not buy any of these kits anymore. I wish I could make them myself, but it's not worth the trouble right now. I built a paia synth and it all works, so I think i should be able to do this right. Too bad.

I am seeing this same problem with my RBBB freeduino connected with a usb to ttl ftdi cord.I can repro the problem consistently and if I unplug the cable from the computer then plug it back inI will be able to load the next time, but not again until I unplug/plug.

I would like to clarify that the subject of this thread should be "Problem with Freeduino Serial v1.0 board". Freeduino Serial v2.0 board is MAX232 (or compatible chip) based and eliminates the problems reported on this thread. The confusion comes from the fact that Freeduino Serial v1.0 board was based on the "Arduino serial v2.0" board, with the "autoreset" hack.

I am seeing this same problem with my RBBB freeduino connected with a usb to ttl ftdi cord.I can repro the problem consistently and if I unplug the cable from the computer then plug it back inI will be able to load the next time, but not again until I unplug/plug.

hmmmmm. Anyone else seeing this?

When you unplug/plug the USB cable, are you resetting the RBBB freeduino or it is powered externally?

I would like to clarify that the subject of this thread should be "Problem with Freeduino Serial v1.0 board". Freeduino Serial v2.0 board is MAX232 (or compatible chip) based and eliminates the problems reported on this thread. The confusion comes from the fact that Freeduino Serial v1.0 board was based on the "Arduino serial v2.0" board, with the "autoreset" hack.

I have no idea on how to change the title of a thread, but I think a couple of posts, like the last ones, trying to clarify the more than confusing naming of Arduino variants is fine.

Product naming is confusing... I started the serial kit as a modified Arduino v2.0 board, with diecimila compatible autoreset, then the Freeduino name started to be known in the community, so I renamed the same product as Freeduino serial v1.0... then I switched to the MAX232 and named the new kit Freeduino serial v2.0

In conclusion:

Arduino serial v2.0 = original Arduino team PCB design. Some PCBs are still sold, but no kits or assembled boards exist

Freeduino serial v2.0 = New serial board design. Introduced MAX232 compatible chips as RS232 driver and removed transistors. Still has autoreset feature, so it is diecimila compatible. If you have a PC or laptop with RS232, it is a cheaper alternative to the more expensive USB boards... and it works just great!